All posts for the month August, 2012

Were all the GMD interceptors deployed before they had successfully killed a target in an intercept test?

At a glance, this might seem impossible. After all, the deployment of the 30th GBI interceptor did not occur until mid-2009, and the MDA states that it had conducted three successful intercept tests by the end of 2008. However, a closer examination, taking into account that there are currently two different types of GBIs deployed and a recent revelation about the GBI test program, indicates this may actually have happened. The publicly available information indicates that, at best, a few of the CE-I versions of the GBI interceptor may have been deployed one or two days after it first successfully killed a target in a test.

Figure 1: GBI Silo Field 2 at Fort Greely, Alaska. The lower inset shows a GBI being loaded into a silo.

Modern systems for visible detection and tracking of space objects, such as the Ground-based Electro-Optical Deep Space Surveillance (GEODSS) system are typically built around a telescope equipped with a charge-coupled device (CCD) detector. This post follows up on the August 20 post on GEODSS by providing some additional information of how the GEODSS CCD operates. In the next GEODSS post, I will make a rough estimate of GEODSS detection capability (in terms of the faintest object it can detect) based on the available information about the telescope and its CCD detector, and compare this to published values.

My previous missile defense post (August 24) compared the three-phase national missile defense (NMD) system plan developed by the Ballistic Missile Defense Organization (BMDO) during the Clinton Administration with the current GMD system. One of the most striking differences in this comparison was the lack of long-range radar discrimination in the current GMD system. While the BMDO plan would have ultimately deployed eight or nine very large X-band Ground-Based Radars (GBRs), the current GMD has only one such radar, the Sea-Based X-band (SBX) radar. Moreover, the SBX, which is somewhat smaller than the GBRs envisioned under the BMDO plan, is scheduled to be semi-mothballed in FY 2013 by cutting its budget by more than 90% and putting it in a “limited test and operations” status.

This post explains why the absence of these large X-band GBR radars leaves the current GMD vulnerable to defeat by the simplest of countermeasures, even unintentional ones. The fundamental problem is that the core radar infrastructure of the GMD consists of Upgraded Early Warning Radars, which have essentially no discrimination capability.

Figure 1. Simulated two-dimensional image of a warhead by a radar with a bandwidth of about 6 GHz, corresponding to a range resolution of about 5 cm.[1]

In September 2000 President Clinton announced his decision not to start deploying the national missile defense (NMD) system his Administration then had under development. In effect, Clinton deferred the deployment decision to the next president. As a presidential candidate, George W. Bush made clear both his belief that the Clinton system was too small and his intention, if elected, to proceed with a larger and more effective system. After his election, President Bush soon withdrew the United States from the Anti-Ballistic Missile (ABM) Treaty and began deployment of what is now known as the Ground-Based Midcourse (GMD) national missile defense system.

After ten years of deployment (the U.S. withdrawal from the ABM Treaty went into effect on June 13, 2002) it is interesting and informative to ask how the current GMD system compares with the NMD system plan developed during the Clinton Administration. In almost all important respects (number of interceptors, radar capabilities), the current GMD national defense system fall far short of what the Clinton plan called for.

The table below summarizes the systems. More detailed descriptions and an element-by-element comparison follows.

Table 1. Comparison of the current GMD national missile defense system with the initial (C-1) and final (C-3) phases of President Clinton’s proposed NMD system.

In yesterday’s post on the GEODSS optical space tracking system, I frequently referred to the visual magnitudes of space objects and to the object sizes corresponding to those brightnesses. This post briefly discusses brightness and visual magnitudes and the standard procedure for assigning a size to an object of a given magnitude.

The GEODSS (Ground-based Electro-Optical Deep Space Surveillance) System is the United States’ primary deep space tracking system. The Deep Stare upgrade of GEODSS, carried out in about 2003-2005, greatly increased the capabilities of the system. GEODSS uses a total of nine large telescopes at three different locations to track space objects by using reflected sunlight, (and thus can only operate at night and when not cloudy). It can likely detect objects with sizes under 0.5 meters in geosynchronous orbits. GEODSS provides about 60% of all the SSN’s deep space (orbits with periods greater than 225 minutes) observations and nearly 80% of all geosynchronous observations.[1] There are over two hundred GEODSS-tracked objects that are not tracked by any other sensor.[2]

The Aegis SPY-1 radar is part of the Aegis combat system deployed on U.S. Navy cruisers and destroyers as well as on a number of foreign ships. Originally designed as an air defense system, the Aegis system on many U.S. Navy ships has been or is being upgraded to include a ballistic missile defense (BMD) capability.

The U.S. Navy currently operates 22 Aegis cruisers (CG-47 or Ticonderoga class), although it currently plans to retire seven of these in FY2013 and FY 2014.[1] Five of the cruisers have so far received BMD upgrades (although one of these is among ones scheduled for retirement).

By the end of 2012, all 62 Aegis destroyers (DDG-51 or Arleigh Burke class) procured through 2005 will have been delivered, with 24 of these having received the BMD upgrades. In 2010, procurement of an additional ten Aegis destroyers began, with first scheduled to be operational in 2016. These ships will be delivered with a BMD capability built-in. The number of BMD-capable Aegis ships (both cruisers and destroyers) is projected to reach at least 39 by 2020. Beginning in 2016, the Navy plans on beginning procurement of a new type of destroyer (the Aegis Flight III) with a more capable (and not yet completely defined) radar, with the first ship scheduled to be operational in 2023.

Aegis Cruiser (CG 72, Vella Gulf). Two of the Aegis antenna array faces are visible on the rear deckhouse. The other two antenna faces are on the forward deckhouse but are not visible here. (Picture source: U.S. Navy)

Aegis Radar Versions

Four different versions of the Aegis SPY-1 radar are currently deployed on U.S. ships. The SPY-1 was a test version of the radar that was never deployed.